[PATCH nft 1/2] parser_json: use stdin buffer if available

[Pablo Neira Ayuso <pablo@netfilter.org>]

Since 5c2b2b0a2ba7 ("src: error reporting with -f and read from stdin")
stdin is stored in a buffer, update json support to use it instead of
reading from /dev/stdin.

Some systems do not provide /dev/stdin symlink to /proc/self/fd/0
according to reporter (that mentions Yocto Linux as example).

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/parser_json.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/parser_json.c b/src/parser_json.c
index ee4657ee8044..4912d3608b2b 100644
--- a/src/parser_json.c
+++ b/src/parser_json.c
@@ -4357,6 +4357,13 @@ int nft_parse_json_filename(struct nft_ctx *nft, const char *filename,
 	json_error_t err;
 	int ret;
 
+	if (nft->stdin_buf) {
+		json_indesc.type = INDESC_STDIN;
+		json_indesc.name = "/dev/stdin";
+
+		return nft_parse_json_buffer(nft, nft->stdin_buf, msgs, cmds);
+	}
+
 	json_indesc.type = INDESC_FILE;
 	json_indesc.name = filename;
 
-- 
2.30.2